Steam food defroster



March 14, 1950 D. F. TROUPE STEAM FOOD DEFROSTER 3 Sheets-Sheet 1 Filed April 21, 1947 INVENTOR. flora/0 fifx'oz/pe ATTORN s March 14, 1950 D. F. TROUPE 2,500,219

STEAM FOOD DEFROSTER Filed April 21; 1947 3 Sheets-Sheet 2 INVENTOR. flma/d E 7701;06

D. F. TROU PE STEAM FOOD DEFROSTER March 14, 1950 3 Sheets-Sheet 3 Filed April 21, 194'? &

INVENTOR.

. m3 gg v Patented Mar. 14, 1950 UNITED STAT tWtTENT OFFICE STEAM FOOD DEFROSTER Donald F. Troupe, Kansas City, Mo., assignor to The Vendo Company, Kansas City, Mo, a corporation of Missouri 11 Claims.

This invention relates to appliances used in. the preparation of foods and more particularly to a steam food defroster, the primary aim being to provide such an appliance that is compact, easy to operate and inexpensive to manufacture.

The most important object of this invention is to provide a steam food defroster having a compartment for the food to be treated and a steam generating boiler having connection with the steam compartment, said boiler being provided with a jacket into which is directed a stream of air passable into the compartment for circulating the steam therein.

Another important object of this invention is to provide a steam food defroster having a wall provided with an inlet opening at one end thereof, plurality of openings at the opposite end thereof and means for directing the steam entering the compartment through said first-mentioned opening toward the stream of air entering said last mentioned openings.

A further object of this invention is to provide a steam defroster having a weight actuated pressure valve for automatically evacuating the steam compartment of excess steam and mechanism associated therewith and operable by a unique door latching assembly for clearing the compartment of all steam prior to opening of its door.

A still. further object of this invention is to pro vide a steam food defroster having a water reservoir for supplying water to the steam generating boiler wherein is mounted a thermostatically controlled valve for permitting the passage of water into the boiler When the latter reaches a predetermined temperature.

Other objects of this invention include the way in which pressure equalization in the water reservo'" is obtained by use of the steam from the boiler, the manner in which all the aforesaid themostats, valves, fan and heating element are controlled by the door latch mechanism, and the way in which all the component parts of the assembly are assembled into a compact unit.

Many additional objects of this invention will made clear or become apparent during the course of the following specifications, refere being had to the accompanying drawings .rrfiIEZll'l Figure l is a front-elevational view of the steam food defroster made in accordance with my present invention, parts being broken away for clearness.

Fig. 2 is a rear-elevational view thereof, parts being broken away to reveal details of construction.

Fig. 3 is a side-elevational view thereof, parts being broken away and portions thereof being in section for clearness. I

Fig. 4 is a fragmentary, detailed, enlarged view of the pressure valve assembly showing the same partially in section.

Fig. 5 is an enlarged, fragmentary, sectional. detailed view of the relief valve per se.

Fig. 6 is a fragmentary, elevational View of the compartment door, parts being broken away to reveal the door latch construction.

Fig. 7 is a fragmentary, side-elevational view of the door, parts being broken away to illustrate the manner in which the latching mechanism locks the door when in a closed position; and

Fig. 8 is a schematic view of the wiring diagram for the electrical system forming a part of the defroster.

It is contemplated that the steam food defrost.- er, about to be described, be adapted for use primarily in airplane galleys. It is common knowledge that food served to airplane passengers is automatically pro-cooked and carried by the airplane in a frozen condition. It becomes necessary therefore to provide means for defrosting such food, which means is also capable of further cooking such food if desired. Space being an important factor, as well as weight, the steam food defroster, forming the subject matter of this application, is therefore designed in view of these problems as will hereinafter be more fully set forth.

In the drawings a cabinet generally designated by the numeral iii has a compartment I2 at one end thereof of double wall construction to provide suitable means for receiving insulation (not shown). A number of shelves [4 within the compartment l2 are slidably supported through the medium of brackets IS in the usual manner. Cabinet to carries, in addition to compartment 12, a water reservoir l8, a steam generating boiler 20 and a fan 22. Water reservoir 18 is placed into communication with the boiler 2!! through the medium of a pipe or conduit 24 having a valve at the lower-most end thereof mounted Within a housing 26. This valve is in communication with a short pipe 28, which pipe 28 is in turn connected to the boiler 20.

A pipe or conduit 30 leads from the upper end of the boiler 20 and communicates with an opening 32 formed in the back wall 34 of compartment i2. A jacket 36 completely surrounds the boiler 20 in spaced relation thereto and a portion of the wall 34 of compartment [2 forms one wall of this jacket 36. This portion of the wall 34 has a. plurality of perforations therein as at 38 for placing the compartment I2 into communication with the jacket 36.

Fan 22, having a suitable electric motor 40, is disposed to direct streams of air into the jacket 36. A suitable opening in jacket 36 (not shown) places fan 22 in communication with the interior of jacket 36. It is clear that this fan 22 will direct streams of air against the hot boiler through the perforations 38 and into the compartment I2.

A baffle plate 42 is mounted within the compartment I2 in spaced relation to wall 34 and extending across the entire width of compartment I2. This bafile plate 42 terminates directly above perforations to the end that steam entering the inlet opening 32 will pass downwardly between plate 32 and wall 34 as indicated by arrows in Fig. 3. This steam will contact the stream of air entering perforations 38 and be circulated throughout the compartment I2.

A steam valve is interposed within the conduit 30 mounted in a housing 44. Each of the valves within housings 26 and 04 respectively are actuated by solenoids, the water valve in housing 26 having connection with a solenoid 46 and the steam valve within housing 44 being operated by a solenoid 48. A thermostat 50 is disposed within jacket 36 adjacent the boiler 20 for controlling the operation of solenoid 46 to thereby operate the water valve when the temperature of boiler 20 reaches a predetermined point. A suitable heat element 52 is disposed adjacent to the boiler 20 and this heat element is controlled by a thermostat 54.

A door broadly designated by the numeral 56 is swingably mounted upon the cabinet I0 through the medium of hinges 58 and this door 56 is swingable to and from a position closing the compartment I2. Door 56 carries a conventional handle 59 and a substantially circular disc member 60 is mounted within this door 56 and joined to the handle 59. Door 56 also carries a pair of bars 62 and 64 reciprocable vertically in opposite directions. These bars 62 and 64 are substantially L-shaped and each carries a pin 66 at the free end of the leg 68 thereof. These pins 66 extend into a respective slot "I0 formed in the disc 60. These slots I0 are all of peculiar arcuate design in the nature of that illustrated in Fig. 6 and rotation of the disc 60 by actuation of handle 59 causes the pins 66 to slide in the slots '10 and thereby reciprocate bars 62. The outermost free ends of each of the said bars 62 are beveled as at 12 and the cabinet I0 carries a pair of outwardly projecting extensions I4 having openings 16 therein for receiving the beveled ends I2 of the respective bars. The door 56 has a pair of openings (not shown) for receiving the extension 14 when the door 56 is moved to the closed position.

A master switch I6 mounted within the door 56 carries a plunger I8 in contacting relation with the edge of disc 66. Disc 60 normally holds this plunger I8 at the innermost end of its path of travel where switch I6 is in a position for closing a circuit hereinafter more fully described. When disc 60 is rotated clockwise, as viewed in Fig. 6, a flat portion 80 on this disc 60 is moved to a position adjacent to the plunger I8 of switch 16, permitting this plunger 10 to move outwardly and open the aforesaid circuit. It is notable at this juncture that the switch I5 is in the circuit opening and circuit closing position when the door 56 is open and closed respectively.

A conduit 82 is in communication with the c0mpartment I2 at one end thereof and with a chamber 84 at its opposite end. This chamber 34 has swingably mounted therein, as at 86, weighted valve moveable to and from a position closing the open end of conduit 82 which terminates within the chamber 84.

A solenoid 90, mounted upon this chamber 84, has a plunger 92 reciprocable toward and from chamber 84 and this plunger 02 is provided with a spring or other yieldable means (not shown) for maintaining the same at the uppermost end of its path of travel away from chamber 04. When this solenoid is energized, its plunger 92 is driven toward chamber 84 and against the action of its spring to a point where this plunger 92 contacts a pin 94. Pin 94 is slidably mounted within an opening formed in one wall 96 of chamber 84 and a leaf spring or the like 98 yieldably holds pin 04 at the uppermost end or its path of travel. Actuation of pin 94 by plunger 92 causes this pin 94 to contact weighted valve 04 whereupon the latter swings upon pivot 86 to open conduit 82. Condensate, steam, vapor or other matter passing from compartment I2 through conduit 82 enters chamber 84 when valve 88 is open and then passes outwardly through opening I00 formed in one wall of chamber 84.

In the event that it becomes necessary to mount the Water tank I8 in a position where sufficient water will not be supplied to the boiler 20 by the action of gravity, equalized pressure is maintained in this tank I0 by connecting the same to the steam pipe 30. This connection is made through the medium of an equalizing tube I02. A pipe I03 interconnects the housing 44 having the aforesaid steam valve mounted therein and the chamber 84 as illustrated in 2 and 3 and a relief valve I04 is interposed in this pipe I03 adjacent to the housing 44. The valve I04 comprises a hollow head I06 having a spring I08 for yieldably urging a ball H0 to a position closing outlet opening I I2 in head I00 which opening H2 is in direct communication with housing 44.

' In the event the pressure within the tube 30 becomes too great, valve I04 will automatically open to permit excess steam to flow from housing 44 into the valve housing I06 and thence into the pipe I03 where this steam is free to escape into chamber 84 and outwardly from opening I00. It is possible therefore to maintain a predetermined pressure within compartment I2 by merely adjusting the tension of spring I08 forming a part of relief valve I04.

Referring now to Fig. 8, the numerals I I4 and H6 designate lead lines from a source of elec trical energy such as a battery (not shown) and the numeral I I8 designates a switch mounted on door 56 as illustrated in Fig. 1 for closing a circuit through the various electrically operated parts above described. Also as above set forth, cam actuated switch 16 is closed when door 56 is closed and handle 59 is actuated to the door locking position.

A circuit is therefore closed from lead line II4 to line II6 when switches I6 and H3 are closed to energize a master relay broadly designated b the numeral I20. This circuit is traced as follows:

From lead line H4, through wires I22 and I24, closed switch I I8, wires I24 and I26, closed switch '16, wires I28 and I30, relay I20, wires I32, I34, I36, I38 and I40, to lead line IIE.

It is notable that relay I20 is a master relay wound not only to constitute the solenoid 90 but to close contact points I42 and I44 forming a part "of relay I20. Thus with switches H8 and 16 both closed, the solenoid'90 is maintained in an energized condition to the end'that its plunger 92 is moved inwardly against the action of its spring so that valve 88 is free to swing on pivot86.

With contact points I42 and I44-held closed by energization of relay I20, a number of circuits are closed and Ian 22is immediately energized through the following circuit:

From lead line II'4, through wires I22 and I46, closed contact points I42 and I44, wires I48 and I50, motor 40 of.,fan,22,,1wires I52, I54, I34, I36, I38 and I40 to lead lineI l6.

Assuming that the boiler 20 and the heating element 52 therefor are relatively cool at the time switch 16 is closed, upon closing of door 56, the thermostat '54 will be in the closed condition illustrated in Fig. 8 to permit energization of a relay I56 'forholding closed a pair of contactors I58and I60, which contactors I58 and I60 in turn close a circuit through the heating element 52. The circuit for energizing the contactor relay I56 is traced as follows:

From lead .line H4, through Iwires I22 and I46, closed points I42 and 144, wires I48, I62, I64, and I66, relayI56, wires I68, closed thermostat'54 and wires I andlI40 to lead line H6.

With contactors I58 and 1.60 held closed by relay I56, the circuit for energizing the heaters 52 .is traced as follows:

From lead line H4, through wire I12, closed contactors I58 and I60, wire I14, heating element 52 and wire I16 to lead line I I6.

When theboiler '20 reaches a predetermined temperature, thermostat .50 will be closed permitting energization of solenoid 4.6 which inturn actuates'the water valve withiin hou ing 2 The circuit energizing solenoid 46 is traced as follows:

From lead line I I4, through wires I22 and I46, closed points l 42,'and I44, wires I48, I62 and I18, solenoid 46, wire I80, closed thermostat .50 and wires I82, I36, I38 and I40 .to lead line H6.

Steam generated by boiler 20 is then free to flow into compartment I2 because the steam valve within housing 44 islheld openb solenoid 48. This solenoid 48 is continuously energized through the following circuit:

Fromlead line .I I4 through wires I22 and I46, closed points I42 and I44, wires I48, I62, I64 and I84, solenoid'48 and wires I86, I38 and I40, to lead line I.I.6.

When master switch I I8 is closed, the operator is notified, throughthe medium of pilot light I80, that the above described circuits will be immediately closed upon closing of door 56. The circuit for this light I829 is traced as vfollows:

From lead line H4, through \wires I22, I24, closed switch I I8, wires I24 and I82, lamp I80 and wire I84 to ground I86.

The operation of the above described steam food defroster has been made clear as the component parts thereof where described and it is clear that opening of door 56 will ,de-energize all the circuits illustrated in Fig. .8. The heating element v52 will cease to operate, the steam valve Within housing 44 will close to prevent entrance of further steam into compartment I2, and such steam as will continue'to'be,generated by boiler 20, as the same cools, will escapethrough relief valve I04. The water valve within housing 26 will immediately close on de-energization of its solenoid 46 irrespective of the condition of thermostat 50 to prevent further flow of water from tank I8 to boiler 20. This flow of water will be checked both with respect to its gravitational'fiow and flow thereof induced by steam entering tank I8 through conduit I02. Obviously de-energization of relay I56 will open contacts I 58 and I60 to de-energize heaters 52 and deenergization of relay I20 will not only open all the circuits including that of motor 40, but will ole-energize solenoid 90 whereby valve 88 is automatically opened to evacuate compartment I2 prior to opening of door .56.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. A steam food defroster of the class described comprising a normally closed compartment for the food to be treated; a steam generating boiler; a water reservoir having connection with the boiler; a conduit forplacing the boiler into comrnunication with. the compartment, said com-- partment havingan access opening; a closure for said opening movable to and from a closed position; aflatch for locking saidclosure in said closed position; a pressure valve for evacuating the compartment of excess pressure when the closure is in said position; and structure operable by said latch for actuating the valve as the latch is manually moved toward the unlocked position.

2. A steam food defroster of the class described comprising a normally closed compartment for the food to be treated; a steam generating boiler; a water reservoir having connection with the boiler; a conduit for placing the boiler into communication with the compartment, said compartment having an access opening; a closure for said opening movable to andfrom a closed position; a, latch for locking said closure in said closed position; a pressure valve for evacuating the compartment of excess pressure; andstructure operable by said latch for-actuating the valve as the latch is manually moved toward the unlocked position, said compartment having an open end outlet pipe, said valve comprising a gate swingable-by the action of gravity to a position normally closing said end of the pipe.

3. A steam food defroster of the class described comprising a normally closed compartment for the food to be treated; a steam generating boiler; a water reservoir having connection with the boiler; a conduit for placing the boiler into communication with the compartment, said compartment having an access opening; a closure for said opening movable to and from a-closed position; a latch for locking said closure in said closed position; a pressure valve for evacuating the compartment of excess pressure; and structure operable by said latch for actuating the valve as the latch is manually moved toward the unlocked position, said compartment having an open end outlet pipe, said valve comprising a gate swingable by the action of gravity to a position normally closing said end of the pipe, said structure includinga solenoidhavi-ng a reciprocable plunger for actuating the swingable gate, said solenoid beinginoperable when said latch is locked where- .bysaid valveis free for actuation by excess pressure in the compartment.

4. A steam food defroster ofthe class described comprising a, normally closed compartment for the foodto be treated; a steam generating boiler; a water reservoir having connection with the boiler; a conduit for placing the boiler into communication with the compartment; a pressure valve adapted to evacuate the compartment of excess pressure; a solenoid for actuating the pressure valve, said compartment having an access opening and a closure for the Opening; a switch for closing an electric circuit through the solenoid; and a latch movable to and from a position locking the closure in the closed position, said latch having means for moving the switch to and from a closed position as the latch is moved toward and from the locked position respectively, said solenoid having parts for actuating the valve when the solenoid is de-energized upon opening of said switch.

5. A steam food defroster of the class described comprising a compartment for the food to be treated, said compartment having an access opening, a closure for the opening, and a manually manipulable latch movable manually to and from a closure-locking position; a steam generating boiler having connection with the compartment; a heating element for the boiler; a water reservoir in communication with the boiler; a valve for controlling the flow of water to the boiler; a valve for controlling the flow of steam to the compar ment; a fan for circulating the steam in the compartment; a valve for controlling evacuation of steam from the compartment; solenoids for each valve for actuating the same; a pair of thermostats for the water valve and the heating elements respectively for controlling the operation of said water valve and heating element; a control switch for closing circuits through said fan, all of said solenoids, both thermostats, and the heating element; and means forming a part of said latch for moving the switch to and from a closed position as the latch is moved toward and from a closure-locking position respectively, whereby said circuit is tie-energized when the closure is unlocked.

6. In steam food defroster of the class described, a. steam compartment for the food to be treated, said compartment having an access opening in one side thereof; a door swing-able to and from a position closing said opening; and a manu ally manipulable latch assembly for locking said door in the closed position, said assembly comprising a handle; a rotatable disc on the handle; a pair of reciprocable bars on the door; means interconnecting the disc and said bars for actuating the latter upon rotation of the disc by manual manipulation of said handle; and means on the compartment cooperable with said bars for holding the door closed when the bars are at one end of their paths of travel respectively; means for supplying said compartment with steam under pressure; and structure having electric control mechanism for evacuating the compartment, said disc having a cam surface disposed to actuate said mechanism to a position for operating said evacuating structure as the disc is rotated from the door-locking position toward a position unlocking the door.

7. In a steam food defroster of the class described, a normally closed steam compartment for the food to be treated; structure for supplying said compartment with steam under pressure; a fan for circulating the steam within the compartment, one wall of the compartment having an inlet opening for the steam at one end thereof and a plurality of perforations at the opposite end thereof, said fan being disposed to direct streams of air against said structure for heating thereby, through the openings and into the compartment; and means in the compartment for receiving steam from said inlet opening and directing the same toward the perforations and into the stream of air entering the compartment for circulation with the air in the compartment.

8. In a steam food defroster of the class described, a normally closed steam compartment for the food to be treated; means for supplying said compartment with steam under pressure; a fan for circulating the steam within the compartment, one wall of the compartment having an inlet opening for the steam at one end thencof and a plurality of perforations at the opposite end thereof, said fan being disposed to direct streams of air through the openings into the compartment; and means in the compartment for receiving steam from said inlet opening and directing the same toward the perforations and into the stream of air entering the compartment, said steam supply means including a steam generating boiler having a jacket enclosing the same, said jacket being interposed between the fan and said perforations in the wall whereby the air stream is directed against the boiler before entrance into the compartment.

9. In a steam defroster, a normally closed body having a part thereof adapted to contain food to be treated; a steam generating unit housed in said body; means for directing a current of air directly against the unit whereby the air is heated by the unit and circulated in the body; and structure for directing steam emanating from the unit into the path of travel of said current of air.

10. In a steam defroster of the class described. a normally closed compartment for the food to be treated; a steam generating boiler having connection with the compartment; a closed water supply reservoir having connection with the boiler; and means for automatically diverting part of the steam emanating from said boiler to the reservoir when pressure of steam in the compartment reaches a predetermined value.

11. In a steam defroster of the class described, a normally closed compartment for the food to be treated; a steam generating boiler having connection with the compartment; a closed water supply reservoir having connection with the boiler; means for automatically diverting part of the steam emanating from said boiler to the reservoir when pressure of steam in the compartment reaches a predetermined value; means for automatically relieving the reservoir of steam pressure when the latter reaches a predetermined value in the reservoir.

DONALD F. TROUPE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,643,538 Bell Sept. 27, 192? 1,682,448 Vaughan Aug. 28, 1928 2,035,679 Thompson Mar. 31, 1936 2,054,292 Maddocks Sept' 15, 1936 2,102,342 Walder Dec. 14, 1937 2,124,482 Blair July 19, 1938 2,154,021 Abbate Apr. 11, 1939 2,252,541 Arnold Aug. 12, 1941 2,280,894 Cushman Apr. 28, 1942 

